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United States Patent 3,123,460 METHOD FOR COMBATING WEEDS Werner Schiiter, Cologne-Stammheim, Richard Wegler,

Leverkusen, and Ludwig Eue, Cologne-Mulhenn, Germany, assignors to Farbenfabriken Bayer ktlengesellschaft, Leverkusen, Germany, a corporation of Germany No Drawing. Filed Jan. 26, 1960, Ser. No. 4,624

Claims priority, application Germany Feb. 3, 1959 Claims. (Cl. 71-2.3)

The present invention relates to and has as its objects herbicides whose active substance are imido esters or imido thioesters. The active compounds may generally be illustrated by the following formula in which X denotes an oxygen or sulfur atom, R denotes a lower aliphatic radical up to 4 carbon atoms, and in which some or all hydrogen atoms are substituted by halogen, and R denotes a possibly substituted alkyl, alkenyl or alkinyl radical.

The present invention also relates to a method of combating weeds or controlling their growth by using the above shown compounds.

Various substances are known as yet to control the growth of weeds or to destroy them completely. One group of compounds especially used for this purpose consists of plant growth hormones, especially of the series of substituted phenoxy lower alkenoic acids. Other compounds to combat weeds either selectively or completely are such substances which cause destruction because of their phytotoxic properties or the like.

In accordance with this invention it has now been found that compounds of the above shown formula are herbicidal; the invention is more particularly concerned with those compounds of the following formula in which X denotes oxygen or sulfur, R denotes a lower aliphatic radical up to 4 carbon atoms such as methyl, ethyl or propyl, in which some or all hydrogen atoms are substituted by halogen as, for example, trichloromethyl, dichlorornethyl or the a,a-dichloropropionyl radical, and R denotes a possibly substituted alkyl, alkenyl or alkinyl radical, or

An alkyl radical in which some of the hydrogen atoms are substituted by halogen, or

An alkyl radical which is substituted by hydroxyl groups or amino groups, or

An alkyl radical which is substituted by alkoxy groups,

An alkyl radical, which is substituted by phenoxy groups which may be further substituted in the nucleus by halogen atoms, or

An alkyl radical which is substituted by aromatic or heterocyclic radicals, or

An alkyl radical which includeshetero atoms such as nitrogen, sulfur or oxygen, or

An alkyl radical which is substituted by hydroxyl groups which may also be acylated. The aliphatic acyl radicals may be further substituted by halogen atoms or carboxyl groups. They may also be unsaturated. These hydroxyl groups may likewise be acylated by aromatic radicals which are substituted in the nucleus by halogen,

ice

nitro, carboxyl or alkoxy groups. The hydroxyl groups may also be acylated, for example, by carbamic acids, formic acid esters or an alkyl radical substituted by hydroxyl groups which may be converted into the semiacetal form by the addition of chloral, or

An alkyl radical substituted by hydroxyl groups which may be converted into urethanes, for example, by isocyanates.

The compounds of this class are obtainable from aliphatic halogenated nitriles and the corresponding alcohols, according to W. Steinkopf, Ber. 40 (1907), page 1643, or by an improved method, according to F. Cramer, K. Pawelzik and H. J. Baldauf, Ber. 91 (1958), page 1049, from halogenated aliphatic nitriles, the corresponding alcohol and basic catalysts such as potassium carbonate or sodium alcoholates. Some of the inventively used compounds are known from the literature, others which are not known as yet may be prepared strictly in accordance to those methods for preparing known compounds of the inventively used type.

The imido esters or their derivatives dmcribed above are intended to be used as herbicides, and as weeds in the widest sense of the present application there are to be understood plants which grow in places where they are undesired. It has been found that germinating seeds are completely prevented from further germination, or that seedlings are damaged to such an extent that they die.

It has further been found that the germination-inhibit ing or damaging action is chiefly directed against grarnina so that the compounds may be used as selective herbicides.

The weeds are destroyed before growth by a treatment of the soil, or early in spring by the use of the compounds as total herbicides. When the compounds are used as selective herbicides the treatment of the cultivated plants is carried out after sowing.

The agents are applied with a liquid or solid diluent or extender. Solid extenders are preferably talc, chalk, bentonite, kieselguhr, clay, silicate and the like. Liquid dilutions 0r solvents are especially water, together with suitable auxiliary solvents and emulsifying agents. An addition of conventional herbicides or fertilizers is possible or even desirable. If used in the form of aqueous or oily dispersions, emulsions or solutions they may contain wetting agents, emulsifiers or other dispersing agents, especially those of non-ionic type such as aryl-hydroxy polyglycol ethers.

The solutions used in the examples are prepared with the aid of auxiliary solubilizing agents such as acetone or dimethyl formann'de, emulsifier (non-ionic emulsifiers such as benzyl-hydroxy-diphenyl polyglycol ether) and water.

The following examples are given for the purpose of illustrating the present invention:

Example 1 In green-house tests mixed mustard and oath sowings were sprayed with 0.2%, 0.1% and 0.05% solutions 24 hours after sowing the solutions were prepared as said above, i.e. by mixing the active substances with twice their amount of acetone as auxiliary solvent and the same amount of nonylphenol polyglycol ether as emulsifier. The compounds were diluted to the concentration shown above. mg., 50 mg. and 25 mg. of active substance were used per 100 square centimeter. Three weeks after the treatment the pots were evaluated. This evaluation is based on 4 grades of damage.

Mustard oat, Pre-emergence 100 mg. Compound 50 mg. 25 mg.

I11 0 m 0 m 0 C1 CC-OCH 2-3 3 2-3 3 1 2-3 EEC-C C1g--OOCH3 3 3 1-2 3 3 CH3 C13CCO-Cfl 1-2 2 0 1 0 0 NH CH:

ClaC-COCH2C o1; 1 3 1 2-3 0 2-3 C13C-C-OCH2CH2C1 2-3 2 2 1 1 1 Cl3C-C-OOH1CH=OHa 3 3 1-2 2-3 0 1-2 ChO-OOCHzOHgOH 1 3 0-1 3 0-1 3 C1 C-COCH2CHCHzO1'-I 1 2 0 l-2 0 0-1 NH OH C13C-COCH2GH2O 2-3 3 2 3 2 3 ClaCCO-CHaCH2-OCl 3 3 3 3 3 2-3 ClaCOOGHzCH2-O 3 3 3 2-3 3 2-3 CHCO-CHz-CH2-O-Cl 3 1-2 3 1 3 0 01 a.

Cl CCOOHq-CHaOCCHzCi 3 2-3 1-2 1-2 0 0 NH ll C1aC-COCH2-CHzOC-C C13 2 2 0-1 0-1 0-1 0-1 ClaC-C-O-GHzGHqOC-OH=CHCOOH l 1 0 0 0 0 I IH ll 013o-o-0oH1-CH20-CC1 1 0-1 0 0 0 0 CH3 ClaCCOCHzGH:O-O-N 3 2-3 12 2 1 1-2 IQYH (H) CHa C1 OC0CH;-CH;OCH-C Ola 2 3 1 3 0 3 ClaC-C-OOHz-CHnO-C-NH-C1 2-3 0 2 0 0 0 I IH ll C1aCCO-CHa-CEGCH2O 3 3 The figures mean: The effect of the active substances on seedlings varies 0:110 elfect as can be seen from the above table. It is further evident 1:75 germinated, marked damage to seedlings that some of the compounds have a pronounced action 2=less than 50% germinated or severe damage to seedlings against germinating grass seeds whilst others are also 3:110 germination or destroyed after germination 75 suitable as total herbicides.

Further active compounds which were tested and also showed a good activity are as follows:

4 weeks after germination, the degree of damage to the seedlings was evaluated from the day of sowing).

C1\ :no ellect oH-o-s-omon2 0rr 5 l sli ht damage 11 2:1narlred damage :51" We Inc-o o12o s o1r2-omon 3 damao L H .:severe damage, but plants not destroyed NH 5 :plants completely destroyed Cl5C-C-SCI-I CH OCII [I 2 Z 3 1 Tue results show that the compounos are suitable for 01 NH selective weedl illing in the pro-emergence state.

When the compounds used in Example 2 are diluted /CHC O OH2 CH2O with kaoline and admixed with the soil before sowing, 01 NH equal results are attained.

/-w 15 We claim: fi 1. A method of combating weeds which comprises NH applying a phytotorric concentration of a compound of the tollowirv formula onco-o om D NH y ClaC |fO-C1;I2R3 o1io-oo-o1no1-n s ornoin NH NE in which R stands for a member selected from the group consisting of hydrogen, lower alltyl radical up to 4 carbon Cl C-C-OCH -C1I 0 G atoms, halogen-substituted lower allryl radical, hydroxyl- Q 1 L substituted lower alkyl radical, lower alkoxy-substituted lower alkyl radical, phenom-substituted lower alkyl radir cal, carboxy-substituted lower alkyl radical, lower 11 ll alkenyl-substituted lower alkyl radical, and lower alkinylsubstituted lower alkyl radical. 2. A method of combating weeds which comprises Il ll applying a phytotoxic concentration of a compound of L COOH the fOliOWll'lg rorrnula O1 ClzOfiOOHa .NII or orr rr-oo- 1 3C 0 V C 2 3. A method or combating weeds whrcn comprises NH 0 I applying a phytotoxic concentration of a compound of the following formula Cl3C-COCHzCHgOC- -OOH Cl3CCO-CIIz-Cllz0fl 40 M NH 0 NH t I '1 .Y a '1 4 rnehod of conroatm weeds which COR'lP[:l.-B" u H applying a pnytoroxrc concentration of a compound of NH O the following formula Example 2 r 0 c1 O-OOCH "rI2o- -o1 In the greenhouse wheat, oat, Lolmm perenne, beets, 3 u 2 U onions, cotton and mustard were sown in seedling boxes. NH 24 hours after sowing, the boxes were sprayed with so1u- 5. A method of combating weeds which comprises trons at varying concentrations (the amount of water applying a phytotoxic concentration of a compound of the remaining the same) using 40 mg., 20 mg. and 4 mg. of 59 following formula active substance per 400 square centimeter. The solu- C13 trons were prepared as described in Example 1. The rel sult was as follows: NH

COmpound Mg Wheat Oat Beets Gotten Mustard Onions Lolium 40 5 5 5 2-3 2 5 5 CClaCOCHzCCla 20 5 5 4-5 2 2 5 5 g 4 5 4 2-3 0 0 3 5 40 5 5 5 3 2 5 5 C-Cl5-COOH5 2O 5 5 4 0 O 0 5 u 4 5 4 4 0 0 0 3 References Cite-d in the file of this patent UNITED STATES PATENTS 2,553,564 Fein et a1 May 22, 1951 2,569,425 Norris Sept. 25, 1951 2,841,486 Osborn et al July 1, 1958 2,845,298 Osborn et al Aug. 5, 1958 2,898,206 Monoogian Aug. 4, 1959 2,980,734 Kosmin Apr. 18, 1961 OTHER REFERENCES Steinkopf: Ber. 40 (1907), p. 1643. Cramer et al.: Ber. 91 (1958, pp. 1049-1051). 

1. A METHOD OF COMBATING WEEDS WHICH COMPRISES APPLYING A PHYTOTOXIC CONCENTRATION OF A COMPOUND OF THE FOLLOWING FORMULA 